1. Field of the Invention
The present invention relates to apparatus for firmly supporting against upward or downward movement an underground pipe that has been set in a trench and covered with fill dirt. More particularly, the present invention relates to underground pipe support apparatus in the form of an underground stake that includes a pair of clamping members that clampingly engage the outer surface of an underground pipe, the clamping members being securely fastened to the stake to firmly grip and hold the pipe in its original position, relative to the bottom of the trench, so that it does not float to the surface as a result of freezing, thawing, and other movement of the softer fill dirt.
2. Description of the Related Art
The use of stake-type supports for supporting a pipe in a trench has been practiced for some time. In applicant's U.S. Pat. No. 4,126,012, which issued Nov. 21, 1978, there is disclosed an underground pipe hanger that includes a stake portion that is driven into the solid, unexcavated ground below the base of a trench. The stake portion carries a pair of laterally extending arms that are integrally formed with the stake to support a pipe of predetermined diameter. Thus, a number of such hangers must be available with different lateral arm spacings to accommodate pipes of different diameters. Additionally, a variation of applicant's earlier invention incorporating a ring that is carried on a slidable sleeve is also limited to a specific pipe size, thereby requiring a large number of different size ring structures in order to accommodate the wide variety of pipe sizes in normal use.
A form of underground pipe hanger or support that is capable of accommodating pipes of different diameters is disclosed in R.E. McLaughlin et al. U.S. Pat. No. 3,568,455, which issued Mar. 9, 1971. The McLaughlin device includes a steel spike that slidably carries a bracket plate having a cutout portion to receive a pipe. A flexible cable is attached to the bracket plate and is adapted to be passed around the pipe. One end of the flexible cable is firmly secured to the bracket plate and the other end includes a closed loop that is placed in one of a number of notches formed in the bracket to accommodate a variety of pipe sizes. However, the cutout in the McLaughlin et al. bracket is sized for a specific pipe, and thus pipes of sizes different from that of the bracket cutout have localized outer surface stress points because of the small surface area of contact between the pipe and the bracket. Such stress points are particularly undesirable when plastic pipe is supported by the device. Additionally, the McLaughlin et al. bracket is merely held in position relative to the stake by means of a setscrew, which could later permit relative movement between the bracket and the stake, thereby defeating the purpose of the device.
It is an object of the present invention to overcome the shortcomings of the prior art devices described above.
It is a further object of the present invention to provide an improved underground pipe hanger structure that securely grips and engages a substantial circumferential surface area of a pipe, and that is securely carried by an underground stake.
It is an additional object of the present invention to provide an underground pipe hanger made from plastic for light weight, ease of fabrication, and lower cost.